The day started well in Syria with a cease-fire and calm in many areas, but it didn't last. A car bomb in Damascus left five dead and wounded more than 30. There were also clashes in the suburbs of the capital and heavy fighting at a military base on Syria's main north-south highway.

CORNISH: In the northern city of Aleppo, rebel commanders blamed government troops for being the first to break the truce. NPR's Kelly McEvers has spent the last two days in the rebel-controlled areas of Aleppo, and she sent this report.

KELLY MCEVERS, BYLINE: The cease-fire was supposed to start at 6 a.m. today, and for a while, it was quiet in Aleppo. But by 8 a.m., things started going back to their grim normal.

UNIDENTIFIED MAN: (Foreign language spoken)

MCEVERS: This neighborhood is called Bustan al-Basha or Garden of the Prince. These days, it's no garden. Rows and rows of apartment blocks are now empty. Civilians fled weeks ago. The streets are full of rubble. Water lines are busted. The shops are all closed.

(SOUNDBITE OF GUNFIRE)

MCEVERS: Rebel fighters and regime troops have been in a kind of standoff here for weeks, advancing and retreating as one side manages to take a little territory and the other side takes it back.

ABU ANAS: (Foreign language spoken)

MCEVERS: Abu Anas(ph) commands one of two main rebel groups in Bustan al-Basha. He says the trouble today started when regime forces used the quiet hours of the cease-fire to advance beyond their existing positions. He says they tried to take up new positions inside a school.

ANAS: (Foreign language spoken)

MCEVERS: That's possible?

UNIDENTIFIED WOMAN: The soldiers were wearing as civilians, and they tried to sneak in in civilians' cars, and they tried to shoot at them.

MCEVERS: Abu Anas says these regime forces shot and killed two rebels outside the school. He sent his men in to retrieve the bodies.

ANAS: (Foreign language spoken)

UNIDENTIFIED WOMAN: So they just tried to pull the bodies, and one of his men got injured during - pulling one of the bodies.

MCEVERS: As we talk to Abu Anas, a handful of his men, who belong to an Islamist group called Ahrar al-Sham, grab their guns and run down the street. Where are they going?

UNIDENTIFIED WOMAN: They're taking their defense positions.

MCEVERS: But those shots, that's them, right?

UNIDENTIFIED WOMAN: (Foreign language spoken)

MCEVERS: Those shots we're hearing, just the shots, the gunshots.

ANAS: (Foreign language spoken)

MCEVERS: Yes, that's us, says Abu Anas. Now that my men have been attacked by the regime, we're fighting back. In other words, there is no cease-fire. Abu Anas takes us to where he says the regime fired the first shots and killed the two rebels. We climb up a shaky ladder and into a building that used to be a sports facility.

Going up the ladder to see where a guy was standing guard, who they say got killed when he was standing guard. There's fresh blood all over this wall and all over the ground. The building has been trashed by battle. There's broken glass everywhere. Up the stairs and overlooking a courtyard, the rebels show us where first one, then another of their colleagues was shot and killed.

UNIDENTIFIED GROUP: (Foreign language spoken)

MCEVERS: They show us a video of the firefight that ensued.

UNIDENTIFIED GROUP: (Foreign language spoken)

MCEVERS: One injured rebel falls onto a wall and crumples to the floor, bleeding from his leg. Back outside, Abu Anas says even though the rebels seem to be fighting for the smallest swath of territory, he believes it's worth it. He says if the rebels are able to bring down the Syrian regime one day, they'll bring peace and justice to the country. It's an idea that's hard to imagine on a street strewn with burned-out buses and rotting garbage.

(SOUNDBITE OF GUNFIRE)

MCEVERS: At another end of the front line in the neighborhood of Bustan al-Basha, Abu Anas shows us bullet holes he says were made by regime snipers, rubble caused by what he says was a tank shell. Mind you, we can't corroborate Abu Anas' stories. If we tried to approach regime forces from rebel territory, it's likely we would be shot.

Abu Anas walks into a blown-out building and picks up a microphone that's attached to some loudspeakers. He starts talking to the enemy, the regime forces who are dug in just a block away.

ANAS: (Foreign language spoken)

UNIDENTIFIED WOMAN: He says, are you committing to the cease-fire?

ANAS: (Foreign language spoken)

(SOUNDBITE OF GUNFIRE)

MCEVERS: And their response was to shoot?

UNIDENTIFIED WOMAN: Yeah. You heard that.

(LAUGHTER)

ANAS: (Through translator) If we do not stop firing, we're going to answer back. And each bullet, we'll answer back with two or three. And each shell, we're going to shell more.